Tridimensional radiocompass



Nov. 17,1925- c. c. cuLvER wawmnnsrom. mmocouuss 4 Sheet s-Shee t 1 Filed June 1922 Nov. 17,1925 .5

c. c. CULVER 'TRIDIMENSIONAL RADIOCOMPASS' I v I Filed June 9, 1922 4 heet 2 jw'enio r v c. c. CULVER TRIDIMENSIONAL RADIOCOMPASS Nov. ;7, 1925. 1,562,298

FiledJune 9, 1922 4 et 3 Zfive77ior 66mm 0.. W

Nov 1 7 ,19 25. I 1,5 2,298

' "a C. C- CULVER TRIDIMENSIONAL RADIOCOMPASSv Filed June 9, 1922 4 she ts sheet 4 Patented Nov. 17 l925. I

. .-E.IUN I,TEDPSTATES PATENT OFFICE.

Crammer: c. convnn, or WASHINGTON, nrsrmcr or common.-

TBIDIMENSIONAL RADIOCOMPASS.

Application filed June 9, 1922. Serial No. 567,131.

To all whom it may concern:

. Be it known that I CLARENCE O. CULVER,

citizen of the United States, residing at Washington, District of Columbia, have invented certain new and useful Improvements in Tridimension'al Radiocompasses,

. of which the following is. a specification.

'. This invention relates to methods of approaching a landing station 'by sending out radio signals,.and in particular has for one of its objects a system.'-p.f radio compass loops that permits of stationary adjustments of suchloops for varying conditions of loading on an airplane. 5'. In a companion case, I, outlined a skewv method of fixedly adjustinga single coil j radio compass'so that the proper splralling angle of descent can be obtained fora given airplane-and for a given loading of the same. The single coil method, however, has its manifest disadvantages whereasit is a feature of the present invention to variably adjust a-series of fixed coils so thatin case of a forced landing at an intermediate land- 2 ing station, the proper spiralling angle can be obtained taking into account any reduction in ballast asmight occur in a postal route or the like. Es ecially is'this desirable where in a long 1ght the gasoline con: -sumption might bevery great and therefore with every change ofbalanc'e or load, I a new spiralling angle is actually necessary, or at least desirahle' A further feature of the-invention, therefore, is a system of coils which not only gives the necessary component having the desired -athwart angle, ,but which system is also capable of giving any desired nosing an le.

' In order better to isclose the nature of A0 myinvention, I have annexed herewith the accompanying drawings, in which: A

Figure 1 represents a diagrammatic view of the spiralling ath taken by an airplane with respect to t e cone of radiation ema- 45 'nating' from a signaling source;

FigureQ diagrannnaticallyrepresents an arrangement of radio compass colls to give thecomponent' effect of spiral plane flying;

Figure 3'indicates a'schematic arrangement for leading the energy. of the .ra io compass coils to a common receiver circuit;

Figure 4 diagrammatically represents an arrangement ofradio compass coils to ive the component effectpf cylindrical or he ical fly ng? Figure .8 showing the apparent trace of'the resultant co1l for cylindrical flying.

and M of two coils A B C -feet the desired result.

Figure 5'corresponds to-a schematic arrangement similar to Figure 3; a

Figure 6 illustrates the manner of combining both t pes of radio compass coils to. give the com ined effect of conical fl ing; to

Figure 7 corresponds to the com ined schematic arrangements of Figures 3 and 5;

Figure 8. represents diagrammatically an end view of the coil arrangement for'th'e cy lindrical flying component;

Fi ure 8 is a perspective view correspon ing to Figure 8;

Figure 8 corresponds to a plan view of Figure 9 represents diagrammatically a plan view of the coilarrangements for plane spiral flying. V

Figure 10 "schematically represents the apparent .resultant trace of the combined resultant coils for cylindrical and plane spiral flying;

Figure 11 corresponds to an end view of the resultant trace of Figure 9, and

Figure 12 corresponds to a side view'of the resultant trace ofFigures '10 and 11..

Having more particular reference to the drawi and in reference toFi re 1a source on the ground of the lan ing field or station sends out electromagnetic waves of which the circles H correspond to the trace of the lines of magnetic force. An airplane P reaching the vicinity of the landing field would as a first step, circle about the station, r'nakingthe longitudinal axis of the plane a tan ent substantially to the magnetic circles Eat a given height from the ground. The general direction of the center 0' of such circle can be determined by suitably arrangin the turns M V and a: b c d, which latter are angularly disposed with regard to. the athwart axisof the plane. Naturally, with the two coils just mentioned symmetrlcally arranged, the number of turns employed with respect to. a receivin or indicating coil m of a telephone circult T would be equal. However, if the common line A D, a d is not midway between B b or O c the proper proportion of turns vill ef- Similarly, if a common line D' C or d'. 0' of the two coils A B C D, ab' c d is employed for the I same purpose (see Figure 4) the respective erly chosen to give the desired effect in the common receiving coil m. Obviously, all four coils 1W l, M M, can be arranged to act together on the receiving circuit T as indicated in Figure 7.

Having achieved the condition of circular flying, as indicated by the position P in Figure 1, it is obvious that the angle of the plane of the resultant compass coil effects, with respect to the longitudinal axis of the plane, should be so arranged that the airplane will take up some such position as P in order that with the proper nosing of the plane and proper banking the plane will reach the ground of the field along the path of a conical spiral such as S of the figure. Obviously, if the radio compass coil has been properly oriented with respect to the airplane and the airplane properly oriented for conical flying, the angular displacement 0 of the resultant coil with, respect to the longitudinal axis of the plane will be exactly allowed for by the correcting displacement 6 of the airplane axis. 1 In this way, in the conical flying achieved, the plane of the resultant compass coil will always be perpendicular to the circular line of diverging magnetic intensity H. The signals will then, and then only, become increasingly stronger and the aviator will know that he is continually approaching the source of radio energy at the proper descent angle.

The proper descent angle 0 is in general made up of two components, the nosing angle and the proper banking angle. However, the effect of travel of the airplane can also be said to result from a plane spirallin component (excess banking and ,no nosing and a cylindrical helical component (nosing efi'ect per se) with just sufficient banking to keep the cylindrical radius constant. Each deviation of the airplane axis, and consequently the deviation of the radio compass coils carried by the airplane, needs a consequent correction. For clarity, therefore, the above two components will be considered separately.

Turning to Figure 4, it will be assumed that the cylindrical radius of flight is maintained substantially constant and that no nosing effect is introduced. Under these circumstances, the two coils A B C D a b 1; d can be employed by varying the turns M M, of the usual coupling coils with respect to a receiver circuit m T that the effective resultant of the two coils is equivalent to a coil substantially perpendicular to the longitudinal axis of the plane. If, now, cylindrical helical flying is to be resorted to, by properly nosing the plane downwardly, the previous adjustment will require modification so as to keep the" plane of the resultant coil previously referred to in substantially the same cutting plane with respect to the H-lines of radiation as before. The consequence will be that by proper adjustment of the turns M and M, a resultant position, such as that indicated in Figure 8 will be obtained. In plane circular flying the trace aa of Figure 8 would coincide with the athwart axis 00.

In view of the fact, howevcr, that a conical flying effect is desired, the banking of the plane would have to be such that the longi tudinal axis of the plane should never be tangent to the circles of H, but in fact should be tan cut to the conical spiral part indicated in Figure 1. Thus superposed upon the effective resultant coil arranged for by means of the two component coils illustrated in Figure 4, there will be required a second resultant coil whose athwart axis makes an angle with the line D C d 0 of Figure 4. In this way the excess of banking effort to make the plane continually approach the radio source can be corrected for.

By means of the coils A B C D and a b 0 (Z of Figure 2, the above result can be achieved by suitably varying the turns of the couplings M and M (see Figure 3). Clearly, if an excess of banking is to be introduced to provide a spiralling efiect, the respective coupling should be such that the trace of the resultant coil giving the spiralling component should be as indicated by D d- 1 d, in Figure 9.

Combining, therefore, the two resultant coils of Figures 8 and 9 by having all four coup-ling coils M M M M, (see Figure 7) act upon the common receiver circuit m T, the combined trace of the final resultant coil will be as indicated in plan-in Figure 10, in end view as in Figure 11, and in side view as in Figure 12.. The actual efiective position of the final resultant radio compass coil will therefore have as its limiting componental positions either the resultant position of Figures 8*, 8",- of Figure 9, depending upon the preponderance of coupling of the set M M as against M M The two sets of coils are shown in assembly in Figure 6.

In operafion, in approaching a landing field the settings of the coupling coils M M M are made such that the radiation is substantially received athwart the airplane. Thereafter, depending upon the type of airplane and the loading ofthe same the coupling members are set'to give an effective trace of a combined resultant radio compass ooil that is oblique to both axes of the airplane. The banking and nosing of the plane can be so, regulated as to correspond with the setting for the combined resultant coil which manipulation of the airplane controls will then give maximum intensity of signal coupled with the effect of increasing intensity in the signals produced. By such a process as outlined above, the airplane will then always approach the landing field automatically in best position.

' gitudinal axis of said airplane; and further means for guiding said airplane toward said source by'localizing the reception of radiant energy .athwart said airplane at an angle oblique to the longitudinal axis. of said plane.

2. In combination with an aircraft, means for locating a source of radiant ener carried on said aircraft including urther means for guiding said aircraft by a nosing operation with respect to the source of radiant energy, and further including means for guiding said aircraft by a spiral opera tion with respect to said radiant energy source.

In testimony whereof I have aflixed my 20 signature.

CLARENCE 0. CULVEB; 

